Swales

Thanks for the responses. My problems are compounded by:

1. The engineer has only indicated the profile of the swale at the bottom - it has to be a minimum of 9 feet wide.
2. Whilst the upper left hand side of the swale is reasonably easy to estimate (it runs around the perimeter of the construction zone) the right hand side is not so easy, because that edge will fall where the slope intersects with the ground level and that latter level varies.
3. The left hand slope is steep, almost 75 degrees. The right hand slope is shallow, which means that the two platform approach simply doesn't work because the extent of the shallow slope extends further than the steeper, no matter how narrow I make the actual platform.

Ted, in your absence, Leo (at Kubla) has been a star and has proposed another solution. I just haven't had the time to look into that one. I'll report back when I have.

Thanks again to all - I really appreciate the time and assistance given